
package utils;

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBUtils {
    private DBUtils(){

    }
    private static volatile MysqlDataSource mysqlDataSource;
    private static volatile Connection connection;

    private static MysqlDataSource getMysqlDataSource(){
        if(mysqlDataSource==null) {
            synchronized (DBUtils.class) {
                if (mysqlDataSource == null) {
                    mysqlDataSource = new MysqlDataSource();

                    mysqlDataSource.setURL("jdbc:mysql://127.0.0.1:3306/messagewall?characterEncoding=utf8&useSSL=true");

                    mysqlDataSource.setURL("jdbc:mysql://127.0.0.1:3306/messagewall?character=utf8=true&&useSSL=true");

                    mysqlDataSource.setUser("root");
                    mysqlDataSource.setPassword("12345678");
                }
            }
        }
        return mysqlDataSource;
    }


    //1.static connect
    public static Connection getConnection(){
        if(connection==null){
            synchronized (DBUtils.class){
                if(connection==null){
                    try {
                        MysqlDataSource dataSource=getMysqlDataSource();
                        connection= (Connection) dataSource.getConnection();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return connection;
    }
    //2.提供一个关闭资源的方法
    public static void close(ResultSet resultSet, PreparedStatement statement,Connection connection) throws SQLException {
        if(resultSet!=null){
            resultSet.close();
        }
        if(statement!=null){
            statement.close();
        }
//        if(connection!=null){
//            connection.close();
//        }
    }
}
